In the base game the symbols on the Pawns are for flavor, however with these rules each expedition member gets special skills.

LEADER

This pawn can perform an ambush with any card .

NAVIGATOR

You can move or ambush over cracks with a diagonal step .

MEDIC

When your Pawns is ambushed by another player you can bring it to any unoccupied adjacent (in any direction) square to your medic, instead of placing it to your ship. Note: You cannot place the Pawns to North Pole like this.

CARRIER

When your carrier is on the game board you can fill your hand to three cards at the very start of your turn.